A through via (through silicon via, TSV) is introduced as a technology whereby a plurality of semiconductor chips can be mounded at high density. In the case where the semiconductor is silicon (Si), the through via is a conductive region piercing from the back surface to the front surface of the silicon substrate, for example. A plurality of semiconductor chips are electrically connected via the respective through vias to mount the plurality of semiconductor chips at high density; thereby, high-speed data transfer is enabled.
However, since a via hole for providing the through via is formed deep in a semiconductor substrate, the aspect ratio becomes higher and the etching processing thereof becomes more difficult as the miniaturization of semiconductor devices progresses. Consequently, the reliability of semiconductor devices including the through via may be reduced.
For example, until now, for an electrode to be electrically connected to a through via, there has been a case where a faulty connection (open) between an interconnection layer existing between the through via and the electrode and the through via occurs, and as a result a faulty connection between the through via and the electrode occurs. To deal with this, a plurality of through vias have been provided to connect one of the plurality of through vias and the interconnection layer; thereby, a faulty connection has been prevented.
However, since a via hole for providing the through via is formed deep in a semiconductor substrate, the aspect ratio becomes higher and the etching processing thereof becomes more difficult as the miniaturization of semiconductor devices progresses. Consequently, an operational malfunction, a faulty operation, and a yield reduction of semiconductor devices including the through via may be caused.